Recently, with advancement in digital techniques used in electric devices, non-volatile memory devices having a large capacity have been actively developed for storage of data such as music, images, and other information. For example, non-volatile memory devices including ferro-electric capacitor elements have already been used in many fields.
Other than such non-volatile memory devices including ferro-electric capacitor elements, memory devices have been focused because of their characteristics of being easily compatible with conventional semiconductor manufacturing processes and being made in smaller size. Examples of such focused memory devices include: non-volatile memory devices including memory devices of a magneto resistive effect type such as tunneling magnetroresistive (TMR) devices; and non-volatile memory devices (referred to as ReRAM) including memory devices (variable resistance devices) of a variable resistance type having a resistance value variable with application of an electrical pulse and keeping a variable resistance state.
For example, Patent Literature 1 discloses a structure in which a variable resistance element and a diode are arranged in series in a vertical direction, a variable resistance film is formed in contact holes and to be a variable resistance element, and the diode is formed above the contact holes, for allowing the diode to have an effective area size larger than the effective area size of the variable resistance element.
Patent Literature 2 discloses a cross-point structure as a structure for realizing high integration of non-volatile memory devices. The non-volatile memory device having a cross-point structure disclosed in Patent Literature 2 includes a memory cell array including a plurality of memory devices each having a variable resistance element. The memory devices are arranged in via holes in a cross-point area in which a plurality of first lines and a plurality of second lines are arranged orthogonal to each other. In addition, in each memory device, elements having a non-linear current-voltage characteristic (non-linear elements or current steering elements) are arranged in series. These elements having a non-linear current-voltage characteristic selectively activate given ones of the memory devices in the memory cell array. More specifically, for example, use of diodes of a metal-insulator-metal (MIM) type as current steering elements allows the memory devices to perform bi-directional current steering.